36v battery with 48v motor

[guerney]

They now have the tsdz8 so maybe they should opt for that now.

I've read it's the same axle as the TSDZ2, which seems highly likely to make for future painful reading. For that and many of the other issues I've read about, you'll never catch me buying a TS mid-anything. I also avoid reading about them.

Not read the thread for many a month, though most want it to push it's limits it's not fit or designed for.

I'm sure you're right. Punier than the mighty 36V BBS01B.

 

[Az.]

14a would only be in the top mode which I have never used .
Tbh I don't even know how many amps I pull in eco , can't be more then 3 or 4.

TSDZ8 is set to 16A by default as far as I remember, so not that much more than yours.
I wish there was a visible power usage on display.

 

[Ghost1951]

I think that many of us are perfectly suited to what we have bought, or got used to, or learned to get on with. They are different, but we are very happy with them.

It is quite good that there is choice and competition, as long as you do your research before you buy into one, or another. The problem is that if you don't read widely, you can buy into some proprietorial solution that will cost you a fortune, and maybe not be easily reparable, or maybe not even still supported in three or four years. How many threads have there been where people come looking for help with an expensive locked in e-bike, and have little option beyond radical surgery, or the junk yard? Loads, I think.

 

[Ghost1951]

14A and 48V means you have quite powerful "250W"
No wonder it flies

The programming parameters of the motor often keep the actual consumption lower than the bare facts of maximum amps and nominal voltage would suggest. Keep current on the Bafang BBsxxx, when set conservatively, really reduces the continuous power expended. Even set at 80% it will not allow much time at full power.

Like Neals, I run my BBS01 in low assist modes unless I come to a hill which is causing me to have to reach for bottom gear to hold a low speed like 7 mph. The day before yesterday I hit 46 miles on the more than three year old battery before it cut off and the screen went dark. It took me by surprise because the LCD was telling me I was only dropping to 32 volts on hills when using 250 watts. I thought I had at least 5 more miles in the tank. Then I checked the weak group of cells that are often not in balance. They had been near enough in balance last time it was charged three days before (4.15 volts when the battery as a whole was 41.9volts) but that group had gone down to 2.95volts when the battery was at 32volts. That made all go dark. I have long suspected a bad cell in that group.

Funnily enough it evened out again when I re-charged it and it arrived at 4.19 when the whole pack was showing 41.9volts.

 

[saneagle]

Whatever NM my cadence sensored 720W BBS01B exerts on the road via my 20" rear wheel, I reckon power isn't a million Watts away from @saneagle's 48V X 22A = 1050W hub motor via his larger rear wheel.




Untrue! I can climb hills faster to escape your unhinged mates!

Unfortunately, you have that incorrect. You need power to climb fast. Power = torque x speed, so if you use a crank-drive and small wheels, your torque goes up, but your speed goes down.

Let's say, you have your 36v motor's controller set to the default 15 amps. That's 540w from your battery that will be converted to about 378w of climbing power at the back wheel.

My hub-motor running at 48v and 22A takes 1056w from the battery to give about 740w at the back wheel, so my bike will climb twice as fast as yours. If you put the two bikes side by side in a race up any normal steep hill, you'll see the difference instantly. While you're trying to shift from first to second gear, my bike will be gone. Yours would be an embarrassment, by comparison.

When we had the World Championship hill climb in Bristol, you could see the difference. Most of the bikes had 36v and 15 amps, so it was Oxygens and Battribykes against Bosch. The hub-motor bikes immediately got a 10 meter lead, which the Bosch bikes gradually clawed back on the steepest part of the hill, but they never caught up enough to win. IIRC, it was won in 2013 by a guy with a 48v Brompton conversion (hub-motor) because his 48v gave him a 30% advantage. The guys on the Bosch bikes were semi pros, while as the guy, who won against them in 2014 on the Oxygen was the warehouse assistant, who was dragged to the event to help unload the bikes from the van and setup the stand.

You can see the race and the hill here. Actually Andre Lozinski won it in 2012 on an Oxygen Emate, so that was two years in succession that Oxygen won. The crank-drive bikes were nowhere.

Bristol Show

www.pedelecs.co.uk

 

[guerney]

The day before yesterday I hit 46 miles on the more than three year old battery before it cut off and the screen went dark. It took me by surprise because the LCD was telling me I was only dropping to 32 volts on hills when using 250 watts. I thought I had at least 5 more miles in the tank. Then I checked the weak group of cells that are often not in balance. They had been near enough in balance last time it was charged three days before (4.15 volts when the battery as a whole was 41.9volts) but that group had gone down to 2.95volts when the battery was at 32volts. That made all go dark. I have long suspected a bad cell in that group.

Funnily enough it evened out again when I re-charged it and it arrived at 4.19 when the whole pack was showing 41.9volts.

Charge with one of these plonked on? I always do.

 

[guerney]

Unfortunately, you have that incorrect. You need power to climb fast. Power = torque x speed, so if you use a crank-drive and small wheels, your torque goes up, but your speed goes down.

When your mates have passed out on gremlin jizz and crashed all mangled up and minced inside their Batmobile, I'll video that same hill climb at 20A for a side by side speed comparison. Might have to be 19A vs 15A, because I'll need at least two headlights (one front one back).

It's faster. When the facts don't conform to the theory, they must be disposed of.

 

[saneagle]

When your mates have passed out on gremlin jizz and crashed all mangled up and minced inside their Batmobile, I'll video that same hill climb at 20A for a side by side speed comparison. Might have to be 19A vs 15A, because I'll need at least two headlights (one front one back).

It's faster. When the facts don't conform to the theory, they must be disposed of.

It's quite simple. At 19A, you'll get around 480w. Let's say that you pedal at 200w. That would increase your total power from 580w to 680w, which would increase your speed by 17%.

 

[guerney]

It's quite simple. At 19A, you'll get around 480w. Let's say that you pedal at 200w. That would increase your total power from 540w to 680w, which would increase your speed by 26%.

I usually pedal 0.0000001W, maybe a bit less.

 

[Ghost1951]

Charge with one of these plonked on? I always do.

I'm not really worried about y battery lighting up.

I charge it with a 3 amp max charger and never leave it alone when it is charging. It never even gets slightly warm. If I have just been riding the bike, I leave it to settle down for about an hour before beginning to charge it, though this is a bit of over kill, because I mostly ride it in very low PAS so it isn't putting out more than 3 amps when being ridden that way and could not really get warm at all like that.

 

[saneagle]

I usually pedal 0.0000001W, maybe a bit less.

In that case, shields at zero and life at zero, you lose! Press the restart button and try again.

 

[guerney]

In that case, shields at zero and life at zero, you lose! Press the restart button and try again.

I would make more of an effort after breakfast, but I never cycle after breakfast.

 

[guerney]

I'm not really worried about y battery lighting up.

I charge it with a 3 amp max charger and never leave it alone when it is charging. It never even gets slightly warm.

Catastrophic failure within a cell or two while charging could cause very sudden undetected rise of problematic warmth. I don't charge without that contraption, because I'd feel daft if I didn't and something went cells akimbo. Especially considering how cheap and easy it is, much like my wife.

 

[Ghost1951]

Catastrophic failure within a cell or two while charging could cause very sudden undetected rise of warmth. I don't charge without that contraption, because I'd feel daft if I didn't and something went cells akimbo.

Why would a cell go into catastrophic failure if it had not been abused horribly?

How often does this happen?

I might be wrong, so would welcome correction, but it is my impression that the spate of ebike fires we hear so much about are almost always from cells being abused (wrong charger or MASSIVE demand put on them by delivery ebikes rated at 2 kilowatts) or other outright stupid abuse.

Is this incorrect, or are ordinary, prudent cyclist being burned out of their homes by rogue batteries they purchased from reputable makers?

 

[guerney]

Why would a cell go into catastrophic failure if it had not been abused horribly?

How often does this happen?

I might be wrong, so would welcome correction, but it is my impression that the spate of ebike fires we hear so much about are almost always from cells being abused (wrong charger or MASSIVE demand put on them by delivery ebikes rated at 2 kilowatts) or other outright stupid abuse.

Is this incorrect, or are ordinary, prudent cyclist being burned out of their homes by rogue batteries they purchased from reputable makers?

Who the hell knows? What we do know is, there's a rapid temperature rise when they do fail for whatever reason, which if detected before ignitable lithium fumes exude and ignite, might buy a minute or so to throw the damn thing on a shovel inside a metal box out of a window safely before it burns down my house.

60°C is too warm:

 

[Ghost1951]

Maybe you should get a LiFepo4 battery. It would need to be a bit bigger, but they will never go on fire, not even when abused.

 

[Ghost1951]

But I have a window and everything.

I don't understand that post. Maybe I am being a bit thick?

 

[guerney]

Maybe you should get a LiFepo4 battery. It would need to be a bit bigger, but they will never go on fire, not even when abused.

But I have a window and everything.

I'll assemble a smaller version to epoxy to the battery case powered by a small 12V cell or pack at some point, for bus & train commuting with my ebike. And I'll pack a spark plug to smash bus/train windows, in case those little hammers are stolen. Because I'd like to avoid all that energetic coughing charring running and screaming in agony while burning. I'd burn for longer and hotter if I was still really fat.

 

[guerney]

I don't understand that post. Maybe I am being a bit thick?

I've got a window and I'd like to throw a battery outside and watch it explode into flames harmlessly on the lawn, if I miss the water butt. We all have preferences. I prefer when a plan comes together.

 

[Az.]

I don't understand that post. Maybe I am being a bit thick?

It is because you don't follow invention log and you are not familiar with whole catapult/ejection system prepared to act in case of early stages of thermal runaway.